There is an opinion that ecological problems are the most serious ones today. I agree with this statement but I also think that there are other problems that are no less serious than ecological ones.
On the one hand, people can't live without water and air, but they contaminate them with different poisonous chemicals, dropping litter and emitting gases from their automobiles. Moreover, ozone depletion leaves the Earth unprotected from radiation, which is dangerous for the human health. Besides, global warming is a serious problem because it can cause the melting of glaciers and water floods.
On the other hand, people create themselves problems such as wars and global conflicts, making everybody suffer. To make the matters worse, there is a danger of terrorism that we can't stop today and people themselves become the victims of terror attacks. In addition, today there are a lot of undiagnosed diseases, which are dangerous for the whole population on our planet.
Despite the existence of many problems, they can be solved. For example, many wars can be avoided with the help of negotiations and diplomacy. Talking of crime and terrorism, I believe that it is possible to find a solution with enforcing the law and talking to people of other cultures. Having in mind dangerous diseases, I hope that scientists will invent new vaccines to cure every disease and to prevent epidemics and pandemics.
To sum it all up, I would like to say that despite the existence of many issues, ecological problems are still the most serious ones today, and people should address these questions thinking about future generations.